Expense Ratio Calculator — Fund Fee Drag
Find out how much a fund's expense ratio silently consumes over your investment horizon. Enter the investment amount, expected gross return, expense ratio, and years to see the total fee drag, net vs gross final balance, and a side-by-side growth chart.
%
%
years
Wealth lost to the expense ratio through compounding over the full horizon
- 1
Net annual return rate
7% − 1% = 6%The expense ratio is deducted from your gross return every year through compounding. - 2
Gross final balance
10,000 × (1 + 0.07)ⁿ (n = 30) = 76,122.55 - 3
Net final balance (after fees)
10,000 × (1 + 0.06)ⁿ (n = 30) = 57,434.91 - 4
Total fee drag
76,122.55 − 57,434.91 = 18,687.64
How does this calculator work?
Fee drag = P×(1+r)ᵗ − P×(1+r−e)ᵗ, where r is gross annual return, e is the expense ratio, and t is years. Even a 0.5% difference compounds into large sums over 30 years — comparing expense ratios is one of the highest-certainty levers in long-term investing.
Formula
How this is calculated
An expense ratio is deducted daily from a fund's net asset value (NAV), so it reduces your effective annual return by exactly that percentage. A 7% gross return with a 1% expense ratio leaves you earning 6% net — the difference appears trivial each year but compounds dramatically over decades. The fee is never invoiced separately; the fund simply grows more slowly than its benchmark.
The calculator applies compound growth at the gross rate r and at the net rate (r − e) separately, then subtracts to find the drag. Because both trajectories grow exponentially, the absolute gap widens with time: a 1% annual fee on a £10,000 investment at 7% gross consumes roughly £25,000–£30,000 over 30 years — about 25–30% of what the gross balance would have been. The dual-line chart makes this divergence visible.
This model assumes constant annual returns and a constant expense ratio throughout the horizon, which is a simplification — real returns vary and some funds adjust their fee structure. Tax drag, bid-ask spreads (relevant for ETFs), and trading commissions are not included. Use the expense ratio as one input alongside tracking error, tax efficiency, and liquidity when selecting funds.
Frequently asked questions
Broad-market index ETFs typically charge 0.03–0.20% per year. Actively managed mutual funds often charge 0.5–2%. As a general rule, lower is better — fees are the only certain cost in investing, since future returns are unknowable.
Funds deduct the ratio continuously from their NAV, so you never receive a bill. Your units simply appreciate at the gross return minus the fee. This makes the cost easy to overlook in the short term but significant over a long horizon.
Not necessarily, but it is a strong signal — especially for index funds, where the product is otherwise identical. An actively managed fund with a higher expense ratio might justify the cost through superior returns, but evidence shows this is rare over 10+ year periods after fees.
TG we-Calculate Editorial Team. (2026). Expense Ratio Calculator — Fund Fee Drag [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/expense-ratio-calculator
TG we-Calculate Editorial Team. "Expense Ratio Calculator — Fund Fee Drag." TG we-Calculate. 2026. https://we-calculate.com/calculator/expense-ratio-calculator.
TG we-Calculate Editorial Team, "Expense Ratio Calculator — Fund Fee Drag," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/expense-ratio-calculator
@misc{wecalculate_expense_ratio_calculator, title = {Expense Ratio Calculator — Fund Fee Drag}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/expense-ratio-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?